1. Field of the Invention
This application generally relates to image processing system.
2. Description of the Related Art
An image processing apparatus that removes noise contained in image data is disclosed, for example, in Japanese Laid-open Patent Publication No. 2003-259126, as shown in FIG. 1.
An image processing apparatus 200 described in Japanese Laid-open Patent Publication No. 2003-259126 includes a median value calculation unit 212 that calculates a median value of a target pixel in an image block 231 and neighboring pixels of the target pixel (−2, −1, +1, +2). The image processing apparatus 200 also includes a subtracter 213 that calculates a difference value fd by subtracting a median value fmd from a value fi of the target pixel. The image processing apparatus 200 also includes a multiplier 215 that calculates a correction value (G*fd) by multiplying the difference value fd by a gain G set by a gain setting unit 214, and a subtracter 216 that subtracts the correction value (G*fd) from the value fi of the target pixel and outputs the obtained value fout.
By setting the gain G on the basis of the difference value fd, noise contained in image data can be appropriately removed.
Other examples of the related art include Japanese Laid-open Patent Publications No. 2004-355339, No. 2005-323926, No. 2006-041813, and No. 5-307603.